Prsentation PowerPoint

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EGEE
CLIVAR ATLANTIC, Villefranche s/Mer, April 14,
2003 Bernard BOURLES
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• African Monsoon Multidisciplinary Analyses
• Analyses Multidisciplinaires de la Mousson
  Africaine
• Afrikanischer Monsun Multidisziplinäre Analysen
  
• Analisis Multidiciplinar de los Monzones
  Africanos
• Afrikanske Monsun Multidisiplinære Analyser

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Annual rainfall runoff deficit
Factor 2
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A french initiative towards AMMA

• 2000 French community selected the WAM as a
  major research topic with the support of the
  french agencies (CNES, CNRS/INSU, IRD,
  Météo-France)
• Observational and modeling activities exist over
  WA
• (CATCH, IMPETUS, JET2000, PROMISE, AMIP,
  individual works, .)
• ? Need of coordination re-enforcement
• Numerous coming satellites missions (research
  operational) presenting a strong interest for the
  WAM (Clouds, Aerosols, Chemistry, Hydrology)
• ? Need of specific coordinated efforts
  over Africa
• Favorable international context CLIVAR-Africa,
  GEWEX (GHP, GCSS, ), EU programs (WAMP,
  PROMISE, ), ...
• ? Help to re-enforce collaborations between
  countries disciplinaries
• 2001 French proposition open at the
  International Community (White book)
• 2002 Increasing international activity to build
  up AMMA
• Numerous researchers and agencies from African
  countries, Europe, USA have declared their strong
  interest to participate
• Meetings in Africa (Niger), Europe (UK, Germany),
  USA

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AMMA in 2003

• AMMA Scientific Steering Committees exist in
  Africa (AMMANET), UK, US and France
• First draft of International Science Plan is
  nearly finished
•  Commitments  exist from funding agencies (USA,
  UK, France, Germany)
• Projects endorsed by CLIVAR GEWEX

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ACMAD (African Centre Meteorological Application
for Development), Africa AGRHYMET (Centre
régional du Comité Inter Etats de Lutte contre la
Sécheresse au Sahel), Niger CEH (Centre for
Ecology and Hydrology), UK CIRAD (Centre de
coopération Internationale en Recherche
Agronomique pour le Développement) France CNRS
(Centre National de la Recherche
Scientifique) DMNs (National Meteorological
Direction), Africa German Laboratories HGF
(Helmholtz-Gemeinschaft Deutscher
Forschungszentren) ECMWF (European Centre for
Medium Range Weather Forecasting), UK KNMI (Royal
Netherlands Meteorological Institute),
Netherlands ICTP (International Centre for
Theoretical Physics), Italy IRD (Institut de
Recherche pour le Développement),
France Medias-France, France Météo-France,
France MPI (Max-Planck-Institut für
Meteorologie), Germany NASA, USA NCAR, USA NOAA,
USA African Universities (Abidjan, Dakar, Lagos,
Niamey), Africa University of Copenhagen,
Denmark 3 German Universities, Germany 6 Spanish
Universities, Spain 9 UK Universities, UK USA
Universities, USA
Some declared interests
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Main goals of AMMA

• To provide an improved description and
  understanding of the WAM, water cycle,
  variability and associated scale interactions
• (gt better prediction)
• To identify implement an integrated observing
  strategy in WA needed to support research and
  prediction (medium-range, seasonal and climate
  scale)
• To improve our understanding of the atmospheric
  chemistry and aerosols over WA and its global
  impact
• To develop test the long term monitoring of
  surface atmosphere (combining satellite and
  surface networks)
• To implement a strategy to use weather and
  climate observations and modeling/assimilation
  outputs for applications (health, food security,
  water resources, )
• To develop training/education activities for
  African countries

It will be achieved through modeling/assimilation
studies, field and satellite observations,
dedicated field campaigns, database building
dissemination, international collaboration
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Main AMMA Program

• Multi-annual program based on
• A multi-disciplinary approach structuring the
  existing and new efforts
• A nesting of 4 spatial domains and 3 observing
  periods
• Global Scale 2-way interactions between the WAM
  the rest of the globe
• Regional Scale Monsoon Dynamics Scale
  Interactions,
• Continental Water
  Cycle, Land and Ocean Processes
• Mesoscale Mesoscale Convective Systems,
  Tropical Cyclones,
• Catchments and
  Vegetation
• Sub-meso (lt10km) Hydrological Cycle, Vegetation,
  Coupling
•  
•  

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Descrip PERIODS 

• Long Term Observation Period (LOP)
• Inter-annual and decadal variability
• Numerous historical data exist, but need of a
  tremendous effort to collect, homogenize,
  document and distribute those data.
• New observations for the 2002-2010 period
• Enhanced Observation Period (EOP)
• Two whole seasons (2004-2005-2006- ?)
• Document along the zonal and meridional
  transects, the seasonal cycle (surface
  atmosphere) ? Surface memory
• Document the chemical species and aerosols
• Special Observation Periods (SOP)
• Rainy season of 2006 (IOPs of 2 to 4 days)
• SOP 1 Pre-monsoon Onset stages( 10 May- 5
  July)
• SOP 2 Monsoon maximum ( 15 July - 15 Aug)
• SOP 3 Late Monsoon ( 15 Aug. - 15 Sept)
•  

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Importance of the Gulf of Guinea ?
gt Northward penetration of moist air from the
Gulf of Guinea up to the Sahelian domain that
strongly conditions the WAM (mostly the onset
date and intensity, ie in boreal
spring/summer). High sea surface temperature
(ltgt fluxes) variability in this particular
area (equatorial and coastal upwellings, cold
tongue)
e.g. Cold SST anomaly in the GG gt stronger
meridional energy gradient gt stronger WAM
precipitations
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• Oceanographic (french) component of AMMA
• (Ocean Circulation Study in the Gulf of Guinea,
  and its variability)
• Program to study the oceanic parameters and
  circulation
• and their variability in the upper layers of the
  eastern Tropical Atlantic,
• through a) in situ data, b) satellite data,
• c) numerical model results and d) numerical
  experiments.
•  
• Main goals
• - Comprehension of oceanic processes that govern
  the energy exchanges (fluxes heat, humidity,
  carbon) at the ocean-atmosphere interface in the
  Gulf of Guinea, i.e. particularly the sea surface
  temperature, salinity, mixed layer depth (lt-gt
  heat content) and circulation, and their
  variability, mainly from the seasonal to the
  interannual scales.
• Better understanding gt better predictibility.
•  

EGEE
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EGEE
Methods (1) -1/ Analysis and validation of SST
fields (comparison of SST climatologies,
satellital products in situ measurements)
gt representativity of fluxes at the
ocean-atmosphere interface. (expertise of
fluxes calculation of net balance of
heat/salt/movement from validated satellite data
and model results, and "bulk" algorithm gt
comparison with balances of heat/salt/movement
from atmospheric models and evaluation of the
capacity of these models to force the global
oceanic circulation models).   -2/ Analysis of
processes responsible for SST, SSS mixed layer
variability gt Joint analysis of hydrology,
currents, tracers measurements, satellites
products and numerical models. -3/ Analysis
of the boundary layer variability gt
Determination of parameters responsible for the
discrepancy between numerical results and
observations (gt Use of forced biogeochemical
models gt reconstitution of nutrients and carbon
cycles linked to hydrodynamic conditions ?
qualification of dynamical models). gt High
resolution modelisation of the mixed layer (use
of a "pseudo-3D" model the role of surface
heterogeneities approached through the coupling
of the MESO-NH model with the "pseudo-3D" model
they modify the circulation in the lower
atmospheric layers gt modification of
heat/humidity/movement transfers ?
cyclogenesis).    
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EGEE
Methods (2) -4/ Specific oceanographic
cruises (EGEE cruises) and validated transits
gt hydrology, current biogeochemical
parameters (nutrients, CO2) data. gt same
sections carried out at two opposite seasons
during 2004-2006 (late spring and early fall ltgt
monsoon and equatorial upwelling onset and late
periods) simultaneously to the the three years
AMMA Enhanced Observation Period -EOP-.
Maintaining of PIRATA ATLAS moorings current
moorings at 10W and 0-0. SOP Specific
cruises planned in 2006 (SOP-1 and SOP-3). -5/
Implementation of a meteorological station at São
Tomé Island (0 N-6E) gt Extension towards
the east of the Gulf of Guinea of meteorological
measurements available along the equator via the
PIRATA network, associated with a tide-gauge
already maintained by IRD LEGOS.  
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EGEE
Ocean surface rarely accessible from satellite
due to high cloudiness in the Gulf of Guinea
Need of in situ measurements to validate
climatologies and available satellite data
products
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EGEE
 
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EGEE
SPECIFIC CRUISES gt Operational cruises twice
a year (ltgt seasonal variability) in the Gulf of
Guinea during three years (ltgt interannual
variability), running through the PIRATA mooring
sites and repeated sections (10W IS TO BE to
surveyed as much as possible)   Measurements
gt measurements of SST, SSS, meteorological
parameters (wind etc.) gt measurements of
currents, S, T and O2 in the upper layers (0 to
500/1000 m) gt water samplings for salinity,
nutrients and CO2 system parameters gt surface
drifters deployments (SVP, PROVOR) Data should
be transmitted daily for data assimilation in
the operational numerical models, and for
validation/calibration of satellite measurements
(CORIOLIS/MERCATOR).
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EGEE
 Possible tracks of EGEE (2004 2006) cruises
along with PIRATA ATLAS moorings location (black
dots currently operational)
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In the framework of the 2006 SOP (1)   - SOP 1
(May - July) in the Gulf of Guinea during the
monsoon upset.    COULD BE LIKE AREPETITION OF
EQUALANT 2000 gt Surface to bottom oceanic
measurements (T, S, O2, currents, nutrients,
CFCs, CO2) gt Additional atmospheric and
interface measurements - Instrumented mast can
be to provide high frequency (50Hz) measurements
of turbulence, and thermodynamical and radiation
data (0.1Hz). - Upper air soundings and balloons
(could complement the in-land radio sounding
network and document the vertical flow profile
entering over West Africa). - Surface
Marisonde buoys could also be
deployed.   May-June Cotonou -gt 3E meridional
section -gt Pointe Noire -gt Sao Tome -gt
Cotonou June-July Cotonou -gt 3E meridional
section -gt 6S zonal section -gt 10W -gt Abidjan  
EGEE
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In the framework of the 2006 SOP (2) - SOP
3 (end of August - September) in the eastern
tropical Atlantic during the late monsoon and the
eastern tropical Atlantic export off Dakar and
across the Guinea Dome, and repetition of the
10W section. gt air-sea interaction over the
warm waters in relation with cyclogenesis.    gt
Additional atmospheric and interface
measurements - Upper air soundings and balloons
could be launched - Surface Marisonde buoys
could be deployed, maybe along with
Aeroclipper.     Importance of the northeastern
tropical Atlantic area for WAM, ITCZ / SST / TAV
!!!... gt? Contribution/Implication of US or TAV
group ?
EGEE
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LINKS WITH ARGO CORIOLIS
EGEE
Validated transit Example of February 2003 (R/V
Le Suroit) - Deployments of instrumentations
partly funded by EGEE gt PROVOR profilers
deployments (NOAA IFREMER) gt XBTs and SVP
deployments (NOAA IRD) - SST SSS (TSgraph)
and current (ADCP) measurements along the
tracklines.
SHOM Cruise (R/V B-B) in May 2003 15 PROVOR
(green dots) 60 XBTs TSgraph ADCP
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LINKS WITH PIRATA
EGEE
PIRATA ATLAS buoys in the Gulf of Guinea (France
maintenance)
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Link with GOOS VOS network ?XBT /
thermosalinograph lines (maintained by
IRD)   -XBT  5 lines AX05, AX 15 and AX 20
working in operational way.   -ThermoSalinograph
s  3 lines AX05, AX 11, and AX15
EGEE
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Link with US projects (refer to presentation by
F.Schott, TAV activities and proposal) Ex. FACT
(Field Study of the Atlantic Cold Tongue) by
J.Carton et al.
EGEE

• How water is exported poleward out of the cold
  tongue?
• What are the oceanic processes controlling mixed
  layer temperature?

• 50 WOCE-type nearsurface drifters 100 XBTs 30
  GPS-radiosondes

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AMMA International Oceanic Plans (?) (in
progress) - US CLIVAR discussions and
endorsement ? Baltimore Meeting (Nov. 2002),
Washington Meeting (Feb. 2003)... - T.A.V.
implication ? (see next presentation by
F.Schott, TAV Miami Meeting, March 2003) Existing
proposals that contain potential linkages with
AMMA/EGEE - Field Study of the Atlantic Cold
Tongue, by J.Carton et al. - Effect of
atmospheric forcing, upper ocean teleconnections
and feedbacks on tropical Atlantic SST
variability, by S.Garzoli et al. - Dynamics of
the Atlantic Marine ITCZ Complex, by Y. Kushnir
et al. - AMMA International Meeting (NICE, April
10-11, 2003) gt Need of a Working Group in order
to define the Oceanic Studies and Field Cruises
for the International Science Plan of AMMA
document (in preparation, coordination by
T.Lebel, J.L. Redelsperger, C. Thorncroft) W.G.
??? J.Carton, B.Bourlès, G.Caniaux, S.Garzoli,
Y.Kushnir ???...